5 Answers

If you change the extension to something other than one that Windows “knows” and already associates with Excel, including:
.xls
.xlsx
.xlsm
.xlt & etc.
then you’ll have to make a manual association with Excel to open the file (unless you change it to a file extension that is recognized as “to be opened with…” some other program. In that case, Windows will attempt to have the other program open the file and will report an error to you.

All you have to do is go ahead and try it. Make a backup of the file in case it’s important to you, then rename it to MyFile.doc, MyFile.mp3, MyFile.jpg, etc. and see what happens. Assuming the file isn’t able to be opened, nothing should happen. (I’m thinking that if you give it the extension of another Microsoft program, such as .doc, .ppt, .mdb or other associated program – which you have on your machine – then the file might actually be opened, and saving it in that program might cause changes in the header information that will then prevent its re-opening in Excel.)

Go ahead and try with a backup copy or a Dummy.xls file that you care nothing about, and you have nothing to lose if something untoward happens – and you’ll know something new.

After you have changed the file extension you can right-click on the file, select Properties, and eventually find the “Type of File”, “Opens With” and “Change Icon” listings. (You could probably change your file type to .dxls, for example, which will not be recognized as an Excel file, will not be opened by any Microsoft program which “recognizes” the .dxls file type, and still tell it to open with Excel.)

1) right-button click on the file and select “Create Shortcut”
2) right button click the SHORT CUT and select properties
3) Change Icon
4) you can browse the system for other icon files (*.ico) or download an appropriate one of the ‘net. or make them. I made one once but I forget how. here’s a google search